International String Figure Association (ISFA)
The ISFA site introduces "String figures" (designs formed from nothing more than a loop of string), with instructions on how to become a member of ISFA and information on e-mail discussion groups and international gatherings, and links to related sites.
...more>>

Interval Computations
What is Interval Arithmetic?; Languages for Interval Analysis; Numerical Toolbox for Verified Computing (information on the book and software; in German and English): Pascal and C++ versions; Interval Software; Roundings Necessary for Interval Computations;
...more>>

LiveMath - Theorist Interactive, LLC
Web-Shareable computer algebra and graphing software (formerly MathView/Expressionist / Theorist / MathPlus). LiveMath notebooks may be shared via the Web. They are similar to spreadsheets in that a change in one value will ripple throughout the calculations.
...more>>

Magische Quadrate - Paul Heimbach
Techniques for creating 4x4 and larger magic squares using masks that define areas where a specific number will or will not be added (Jupiter squares and Merkur squares, with many examples of each); art based on magic squares and other mathematical models;
...more>>

Math4U2 - University of Applied Science in Augsburg
In German: 2D interactive Java function plotter with animations. Download to run on most computers. It has rich functionality for linear algebra and infinitesimal calculus. Control function parameters and animations. Lessons can be written using XML files
...more>>

Math-Assist - Bernd Schultheiss
Math shareware from Germany (English, French, and German versions are available) for secondary level or high school students and teachers. Math-Assist helps in solving most of the tasks of algebra, geometry, analysis, stochastics, and linear algebra.
...more>>

MathEduc Database - ZDM
MathEduc (formerly MATHDI) is the only international reference database offering a world-wide overview of literature on research, theory and practice in mathematics education. MathEduc also covers education in computer science on the elementary level.
...more>>

Mathematical Institutions - ZIB/Math-Net
A collection of references to some international mathematical institutions, in the following sections: Mathematical Societies; International Centers and Institutions; University Departments in Germany; Mathematics Centers in Germany.
(The main body of
...more>>

Mathematical Miniatures - Gottfried Helms
Number theory heuristics that "fascinated [the author] by their structural beauty." Download PDFs about tetration; Bernoulli-numbers and the Beauty of the Pascal-matrix; Procedures for summation of divergent series using matrices; Mersenne numbers, cyclotomic
...more>>

Mathematikum
Mathematik zum anfassen. Giant soap bubbles, deceiving mirrors, mysterious bridges and more: check out the fun side of mathematics in Gießen, Germany, and put your hands on more than 120 interactive puzzles and exhibits at the world's first mathematical
...more>>

Mathematische Basteleien - Juergen Koeller
A collection of puzzles: pentominoes, Rubik's cube, tangrams, magic squares, and more. Many include directions for building a physical model of the puzzle, as well as comments on solutions. Other topics include numeric palindromes and building an origami
...more>>

mathepower.com - Markus Hendler
A series of calculators for solving problems, for classes 1-10. Primarily in German, but with an English version. Themes include: fractions, geometry, equations, arithmetical operations, trigonometry.
...more>>

Mathepower - Markus Hendler
Online calculators for most calculations covered in the first ten years of school, from basic operations through the first stages of algebra. Available in English, German, and French.
...more>>

maths online - University of Vienna, Austria
A modern mathematics learning site on the Web: details of the project, persons and institutions participating, or project proposals (only in German). The Gallery consists of interactive multimedia learning units (Java applets), each of which includes
...more>>

MendelWeb - Roger B. Blumberg
An educational resource for teachers and students interested in the origins of classical genetics, introductory data analysis, elementary plant science, and the history and literature of science. Constructed around Gregor Mendel's 1865 paper "Versuche
...more>>

My Magic Square - Michael Dormann
Enter a number from 23 to 100, then press the calculate button to see a completed 4x4 magic square, of which any row, column, diagonal, the center square, and the four corners each sums to the number entered.
...more>>

Number World - David Geistert
Key in any positive integer less than 10^15 and press the "Look up" button for properties about it: factorization, divisors, cross sum, equivalence in multiple bases, and more. Number World's math tools include an equation solver, an equation system solver,
...more>>

Place Value Chart - Ulrich Kortenkamp
Tap below this interactive place value chart app's headers labeled "ones," "tens," and "hundreds" to create tokens and begin experiencing bundling and debundling in our decimal number system. Compatible with the Apple iPhone, iPod, and iPad; also available
...more>>

Plastelina Logic Games - Plastelina
Free Flash games include classic constrained "crossing" problems, such as the puzzle of ferrying a wolf, a sheep, and a head of cabbage across a river in a boat that only holds any two of them at once, without leaving the wolf and sheep alone in each
...more>>